title: Structural variations in the glycosaminoglycan-protein linkage region of recombinant decorin expressed in Chinese hamster ovary cells.
abstract: Decorin is a small fibroblast proteoglycan consisting of a core protein and a single chondroitin/dermatan sulfate chain. The structure of the carbohydrate-protein linkage region of the recombinant decorin expressed in Chinese hamster ovary cells was investigated. The decorin was secreted in the culture medium and isolated by anion-exchange chromatography. The glycosaminoglycan chain was released from the decorin by beta-elimination using alkaline NaBH4, and then digested with chondroitinase ABC. These treatments resulted in a major and a few minor hexasaccharide alditols derived from the carbohydrate-protein linkage region. Their structures were analyzed by enzymatic digestion in conjunction with high-performance liquid chromatography. Two of these compounds have the conventional hexasaccharide core, deltaHexA alpha1-3GalNAc beta1-4GlcA beta1-3Gal beta1-3Gal beta1-4Xyl-ol. One is nonsulfated, and the other is monosulfated on C4 of the GalNAc residue. They represent 12% and 60% of the total linkage region, respectively. The other compound has the hexasaccharide alditol with an internal iduronic acid residue deltaHexA alpha1-3GalNAc(4-sulfate)beta1-4IdoA alpha1-3Gal beta1-3Gal beta1-4Xyl-ol, which was previously demonstrated in one of the five linkage hexasaccharide alditols isolated from dermatan sulfate proteoglycans of bovine aorta (Sugahara et al., J. Biol. Chem., 270, 7204-7212, 1995). The compound accounts for 11% of the total linkage region. These structural variations in the linkage hexasaccharide region of the decorin strikingly contrast to the uniformity demonstrated in the linkage hexasaccharide structure of human inter-alpha-trypsin inhibitor (Yamada et al., Glycobiology, 5, 335-341, 1995) and urinary trypsin inhibitor (Yamada et al., Eur. J. Biochem., 233, 687-693, 1995), both of which have a single chondroitin sulfate chain with a uniform linkage hexasaccharide structure, deltaHexA alpha1-3GalNAc(4-sulfate)beta1-4GlcA beta1-3Gal(4-sulfate)beta1-3Gal beta1-4Xyl, containing a 4-O-sulfated Gal residue.
authors.affiliation: Department of Biochemistry, Kobe Pharmaceutical University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kitagawa
authors.forename: M
authors.initials: M
authors.lastname: Oyama
authors.forename: K
authors.initials: K
authors.lastname: Masayama
authors.forename: Y
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: K
authors.initials: K
authors.lastname: Sugahara
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D019765:Chondroitin ABC Lyase / Q000378:metabolism; D002808:Chondroitin Lyases / Q000378:metabolism; D006224:Cricetinae; D058575:Decorin; D016326:Extracellular Matrix Proteins; D006025:Glycosaminoglycans / Q000737:chemistry*; D006801:Humans; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification; D010766:Phosphorylation; D011506:Proteins / Q000737:chemistry*; D011509:Proteoglycans / Q000737:chemistry*; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D013402:Sugar Alcohols / Q000737:chemistry; D013431:Sulfates / Q000737:chemistry; D014316:Tritium
chemical_list: C546878:DCN protein, human; D058575:Decorin; D016326:Extracellular Matrix Proteins; D006025:Glycosaminoglycans; D009844:Oligosaccharides; D011506:Proteins; D011509:Proteoglycans; D011994:Recombinant Proteins; D013402:Sugar Alcohols; D013431:Sulfates; D014316:Tritium; D000469:Alkaline Phosphatase; D002808:Chondroitin Lyases; D019765:Chondroitin ABC Lyase